diff --git a/rag/app/presentation.py b/rag/app/presentation.py
index 45f72adf5..03e89b075 100644
--- a/rag/app/presentation.py
+++ b/rag/app/presentation.py
@@ -40,11 +40,11 @@ class Ppt(PptParser):
         with slides.Presentation(BytesIO(fnm)) as presentation:
             for i, slide in enumerate(presentation.slides[from_page: to_page]):
                 try:
-                    buffered = BytesIO()
-                    slide.get_thumbnail(
-                        0.5, 0.5).save(
-                        buffered, drawing.imaging.ImageFormat.jpeg)
-                    imgs.append(Image.open(buffered))
+                    with BytesIO() as buffered:
+                        slide.get_thumbnail(
+                            0.5, 0.5).save(
+                            buffered, drawing.imaging.ImageFormat.jpeg, quality=80)
+                        imgs.append(Image.open(buffered))
                 except RuntimeError as e:
                     raise RuntimeError(f'ppt parse error at page {i+1}, original error: {str(e)}') from e
         assert len(imgs) == len(